code: def test_init(self):
      train_set = Dataset.from_uir(self.triplet_data)
  
      self.assertSequenceEqual(train_set.matrix.shape, (10, 10))
      self.assertEqual(train_set.min_rating, 3)
      self.assertEqual(train_set.max_rating, 5)
  
      self.assertEqual(
          int(train_set.global_mean), int((3 * 2 + 4 * 7 + 5) / 10)
      )
  
      self.assertEqual(train_set.num_users, 10)
      self.assertEqual(train_set.num_items, 10)
  
      self.assertEqual(train_set.uid_map["768"], 1)
      self.assertEqual(train_set.iid_map["195"], 7)
  
      self.assertSetEqual(
          set(train_set.user_ids),
          set(
              [
                  "76",
                  "768",
                  "642",
                  "930",
                  "329",
                  "633",
                  "716",
                  "871",
                  "543",
                  "754",
              ]
          ),
      )
  
      self.assertSetEqual(
          set(train_set.item_ids),
          set(
              [
                  "93",
                  "257",
                  "795",
                  "709",
                  "705",
                  "226",
                  "478",
                  "195",
                  "737",
                  "282",
              ]
          ),
      )
  
imports: import unittest
  import numpy
  import numpy.testing
  from cornac.data import BasketDataset, Dataset, SequentialDataset, Reader
label_desc: Use image node_id 2 for calling the TestDataset obj's underlying member method code with example usage: obj.test_init() without return types